The usual methods of manufacturing such a cable have lead to difficulties in ensuring that the space inside the bores around the optical fibers is completely filled with the viscous substance. The viscous substance, has to be heated to make it fluid enough to fill the bores, and there is a tendency for it to shrink on cooling, thereby leaving voids.
Preferred implementations of the present invention remedy this drawback and provide a high quality fiber cable by means of a simple and speedy method using apparatus which is both simple and inexpensive.